Ground Conform Outline
Grounded Puppet Physics is a replacement for ragdolls. It is fully implemented as a Control Rig in Unreal Engine.
It is a reliable, deterministic, performant solution that can calculate the ground conforming end pose of the character in a single frame. The bones are traced one by one, and then adjusted based on the position where they make contact with the ground and any other limitations. This forms the target pose. The bone transforms are then interpolated towards target pose in a physics-like manner. Once all bones are processed, the new transforms are fed into a Full Body IK node.
The animation below illustrates the sequential adjustment of the bones, but only the neck bone is being processed, and some features like the bend constraint have been turned off for clarity purposes.